Fused puller switch with fuses which can be removed only when the fused section is first removed



Dec. 12, 1967 H E. SCHLEICHER 3,358,100 FUSED FULLER SWITCH WITH FUSES WHICH CAN BE REMOVED ONLY WHEN THE FUSED SECTION IS FIRST REMOVED Filed March 5, 1966 INVENTOR.

, Hora /d E Sch/e/Cher BY his a/fomeys Z mm/awzw United States Patent M 3,358,100 FUSED PULLER SWITCH WITH FUSES WHICH CAN BE REMOVED ONLY WHEN THE FUSED SECTION IS FIRST REMOVED Harold E. Schleicher, West-Hartford, Conn, assignor to The Arrow-Hart & Hegeman Electric Company, Hartford, Conn., a corporation of Connecticut Filed Mar. 3, 1966, Ser. No. 531,452 5 Claims. (Cl. 200-414) ABSTRACT OF THE DISCLOSURE An insulation switch base has jaw contacts engageable by and separable from blade contacts on an insulation fuse section, which may be telescopingly inserted into the base section. Fuses are mounted in the fuse section on the opposite side thereof from the blades. A removable cover and handle are secured on the fuse section over the fuses to completely isolate and prevent contact with them.

adjacent the ends of the fuses, making it diflicult to separate the contact blades at one end from their spring-clip contacts at the same time as the contacts at the other end separate.

Previously the fuses were exposed by the pulling away of the cover from the base and also were not isolated in separate compartments from each other and from the line and load contacts on the base. Since devices of this type may have 30, 60 and 100 ampere ratings at 600 volts, it is a disadvantage to have so many parts exposed at the moment that the switch contacts separate, particularly if such separation should occur in an emergency under heavy load conditions.

The objects of this invention are to overcome the abovementioned diificulties and disadvantages by providing an improved construction which has a dead front with the current carrying parts being completely enclosed; wherein the fuses are isolated in separate compartments; wherein the section in which the switch contacts disconnect is isolated from the section in which the fuses are located; and wherein the switch contacts are in planes directly adjacent to the plane of the switch handle.

Other objects and advantages of the invention will appear as it is described in connection with the accompanying drawing.

In the drawing:

FIG. 1 is an elevational section view through a fused puller switch embodying the invention.

FIG. 2 is an end elevation view, partly broken away, of the switch of FIG. 1 as seen from the right or left sides of FIG. 1.

3,358,100 Patented Dec. 12, 1967 FIG. 3 is a plan view of the base portion of the switch of FIGS. 1 and 2 after the fuse section is removed.

Referring to the drawing, the switch comprises two main sections. The bottom or base section is a square hollow molded insulation receptacle containing line and load terminals which are connected with spring-clip switch contacts. The top or fuse section is also a square hollow molded insulation receptacle containing fuse clips, fuses and prong-type switch contact blades.

Describing in more detail the base section, designated generally by the numeral 10, it comprises plane parallel end walls 12 and 16 and parallel side walls 14 and 18 perpendicular thereto and a floor 19, the words side and end being used to distinguish and not in a limiting sense. The base 10 also has parallel partitions 13 and 15, spaced from each other and from the side walls 14 and 18, thus providing three parallel compartments which, in turn, are each transversely divided into two equal compartments by a transverse partition 17.

Mounted on the floor of each of these six compartments are identical assemblies comprised of a wire terminal, a bus bar and a spring-clip switch contact. The wire terminals such as 21 in one compartment and 21' in the compartment associated and aligned therewith, may be of any conventional desired construction, such as a tubular member into which may be inserted the bared end of a connecting wire coming through a recess or slot in the wall of the base, eg., 16;- in the wall 12. The wire may be secured in place by a set screw 21s threading into a tapped hole in the top of the member 21.

A bolt such as 22 passing upwardly through the floor 19 at the outer end of the compartment threads into the terminal 21 and secures it on top of a flat conductive bus bar or strip of sheet metal 23 running lengthwise of the floor of th compartment and electrically connecting with a spring jaw or clip-type of switch contact 24-. The spring jaw contact is secured on top of the bus bar 23 by a securing bolt passing upwardly through the floor 19. Thus, the base section provides three pairs of longitudinally aligned separate compartments. One compartment of each pair contains an assembly comprised of terminals 21, bus bar 23 and spring contact 24 while the other compartment of that pair contacts terminal 21, bus bar 23' and spring contact 24.

In this way, in the form of the invention shown, it is possible to connect three line wires to the three wire terrninals of one spring jaw switch contact assembly at one end of the base and three load wires to the three assemblies at the other end of the base.

In order to cover over the six compartments and prevent accidental or inadvertent contact with the line or load assemblies, a plate 30 of fiber or other suitable insulating material is placed on top of the partitions and secured by several screws 29 adjacent the center and sides thereof, threading into metal inserts embedded in enlargements of the partitions. The plate extends from wall to wall in all directions and has rectangular slots 31, 33, 35 over and in register with the three switch jaw contacts on the line side, and three similar slots 32, 34, and 36 over the three switch jaw contacts on the load side.

If desired, apertures such as 37 may be provided in the cover plate 30 over each terminal 21s for passage of a screwdriver so that securement of the line or load wires may be made without removing the cover plate 30.

The fuse section comprises a square hollow molded insulation receptacle having parallel end walls 42, 46 and parallel side walls such as M and a floor 49. The side and end walls are spaced and dimensioned so as to allow the fuse section to telescope into the open top of the base section 10, the walls of which extend upwardly above the inner cover plate 363 a distance approximately equal to the height of the fuse section.

The fuse section is divided in three parallel equal-size fuse compartments by two parallel partitions such as 41 only one being visible (in FIG. 2), that are equally spaced from each other and from the end walls such as 44, only one being visible (in FIG. 2). In each of these compartments is a pair of identical assemblies, one assembly being at each end of the compartment. Each assembly comprises a U-shaped fuse clip such as 50 and 50' of generally conventional form adapted to receive the end cap or terminal of a conventional cartridge fuse 51 which, upon being pressed into the clip, snaps into place and is held there.

The clip is held in place by an overlying leg of an L-shaped switch contact blade such as 52 and 57. which is secured on the floor 49 of the fuse section and over the transverse portion of the clip by screwbolts passing upwardly through the floor 49 and threading into the overlying leg.

The other legs of the L-shaped contacts form switch blades or prong contacts such as 54, 54' which extend downwardly through the slots 49s in the floor 49 which slots 49s register with slots 33, 34- in the base plate which, in turn, are aligned with spring contacts 24 and 24 in separate longitudinally aligned pairs of compartments of the base.

It is important to note that the contacts 24, 24' are closely adjacent the central transverse partition 17. Likewise the blade contacts 54, 54 of the fuse section are located close to the midplane of the fuse section in position to engage the spring contacts 24, 24'. Thus, the switch contacts are located as close as possible to the plane of the handle 6% hereinafter described.

Covering over the fuses in their compartments is a flat insulation cover 62 with a peripheral down-turned lip 64 adapted to rest on the upper peripheral edge of the base walls and to overlap the upper edges of the walls of the fuse sections. The cover is secured on the fuse section by a pair of spaced parallel screwbolts 66. T hese pass upwardly through vertical cylindrical passages in the two compartment walls, the walls being distended to provide room for their passages. The ends of the bolts thread into tapped metal inserts embeddedin the legs of the handle.

The handle is located in the midsectional plane of the fuse section transverse to the fuses and parallel and closely adjacent and between the common perpendicular plane in which the three switch contact blades 24 and three contacts 24, respectively, lie. Locating the handle and the contacts in this way reduces to a minimum the possibility of non-uniform separation of the blades 54, 54 from the fixed contacts 2- 24, since the pulling forces of the contacts of the outside power lines are thus located symmetrically on each side of the middle fuse compartment and as closely as possible to the planes of the contact blades.

From the foregoing, it will be apparent that by pulling on the handle 6% the whole fuse section can be removed from the base section. The blade contacts 54, 54' will separate uniformly at the same time from the fixed base contacts. If current is flowing during the contact separation, arcing will take place in the portion of the base section beneath the plate 34 and will tend to be snuffed out when the blades move out of the openings 33 and 34. Moreover, any arcing that occurs will be entirely isolated from the fuses. Because of the telescoping of the fuse section into the base section, the blade contacts Will be completely inaccessible from contact of any sort from the outside of the switch until the blades have separated from the fixed contacts and the circuit is broken.

To replace the fuses, the bolts 66 are unscrewed, permitting the fuse section and its cover to separate, exposing tht fuses which can then be removed from their clips 50, 5t) and replaced.

The invention may be embodied in switches having different ratings and is particularly adapted for heavy duty Work such as 30, 60 and ampere currents up to 600 volts.

Many modifications within the scope of the invention will occur to those skilled in the art. Therefore, the invention is not limited to the'precise form in the embodiment illustrated I claim: 7

l. A fused puller switch comprising a base section and a fuse section, said base section comprising a hollow insulation receptacle, a plurality of pairs of line and load contacts, means partitioning said base receptacle into a plurality of separate, isolated compartments with one of said contacts mounted in each, said fuse section comprising a hollow insulation receptacle having a bottom and side walls, means to mount a plurality of fuses within said fuse receptacle on the bottom wall thereof, a plurality of blade contacts mounted in said fuse section and extending through its bottom wall in position to engage said line and load contacts, respectively, when said base and fuse sections are joined, the top or open face of said hollow receptacle facing away from said base section, a cover mounted over the open face of said fuse section so that the cover with the side and bottom Walls of the fuse section provides an enclosure for the fuses and their mounting means at all times, a handle on said cover situated in the middle of the cover, and removable means securing said cover on said fuse section, said removable means being removable only when the fuse section is separated from the base section.

2. A fused puller, switch as claimed in claim 1, wherein said blade contacts on the line side are in a common plane and the blade contacts on the load side are in a common plane, both planes being parallel and closely adjacent the plane of the handle.

3. A fused puller switch comprising a base section and a fuse section, said base section'comprising a hollow insulation receptacle, a plurality of pairs of line and load contacts, means partitioning said base receptacle into a plurality of separate, isolated compartments with one of said contacts mounted in each, said fuse section comprising a hollow insulation receptacle having a bottom and side walls, means to mount a plurality of fuses within said fuse receptacle on the bottom wall thereof, a plurality of blade contacts mounted in said fuse section and extending through its bottom wall in position to engage said line and load contacts, respectively, when said base and fuse sections are joined, a cover mounted on said fuse section which with the side and bottom walls thereof provides an enclosure for the fuses and their mounting means at all times, a handle on said cover situated in the middle of the cover, and removable means securing said cover on said fuse section and said handle on said cover, said removable means being removable only when the fuse section is separated from the base section.

4. A fused puller switch as claimed in claim 3, wherein said blade contacts on the line side are in a common plane and the blade contacts on the load side are in a common plane, both planes being parallel and closely adjacent the plane of the handle.

5. A fused puller switch comprising a base section and a fuse section, said base section comprising a hollow insulation receptacle, a plurality of pairs of line and load contacts, means partitioning said base receptacle into a plurality of separate, isolated compartments with one of said contacts mounted in each, said fuse section comprising a hollow insulation receptacle having a bottom and side walls, means to mount a plurality of fuses within said fuse receptacle on the bottom wall thereof, a plurality of blade contacts mounted in said fuse section and extending through itsvbottom wall in position to engage said line and load contacts, respectively, when said base and fuse sections are joined, a cover mounted on said fuse section which withjlthe side and bottom walls thereof provides an enclosure for the fuses and their mounting means at all times, a handle on said cover situated in the middle of the cover having an elongated gripping portion, said blade c tacts on the line side being in a common plane and theblade contacts on the load side being in a common plane, both planes being parallel and closely adjacent and parallel to the plane of the gripping position of the handle.

References Cited UNITED STATES PATENTS 10 BERNARD A. GILHEANY, Primary Examiner.

H. A. LEWITIER, Assistant Examiner. 

3. A FUSED PULLER SWITCH COMPRISING A BASE SECTION AND A FUSE SECTION, SAID BASE SECTION COMPRISING A HOLLOW INSULATION RECEPTACLE, A PLURALITY OF PAIRS OF LINE AND LOAD CONTACTS, MEANS PARTITIONING SAID BASE RECEPTACLE INTO A PLURALITY OF SEPARATE, ISOLATED COMPARTMENTS WITH ONE OF SAID CONTACTS MOUNTED IN EACH, SAID FUSE SECTION COMPRISING A HOLLOW INSULATION RECEPTACLE HAVING A BOTTOM AND SIDE WALLS, MEANS TO MOUNT A PLURALITY OF FUSES WITHIN SAID FUSE RECEPTACLE ON THE BOTTOM WALL THEREOF, A PLURALITY OF BLADE CONTACTS MOUNTED IN SAID FUSE SECTION AND EXTENDING THROUGH ITS BOTTOM WALL IN POSITION TO ENGAGE SAID LINE AND LOAD CONTACT, RESPECTIVELY, WHEN SAID BASE AND FUSE SECTIONS ARE JOINED, A COVER MOUNTED ON SAID FUSE SECTION WHICH WITH THE SIDE AND BOTTOM WALLS THEREOF PROVIDES AN ENCLOSURE FOR THE FUSES AND THEIR MOUNTING MEANS AT ALL AN ENCLOSURE FOR THE FUSES AND THEIR MOUNTING MEANS AT ALL TIMES, A HANDLE ON SAID COVER SITUATED IN THE MIDDLE OF THE COVER, AND REMOVABLE MEANS SECURING SAID COVER ON SAID MEANS BEING REMOVABLE ONLY WHEN THE FUSE SECTION IS SEPARATED FROM THE BASE SECTION. 